Winter Euro-Atlantic atmospheric blocking events have significant
socioeconomical impacts as they cause various types of weather extremes
in a range of regions. According to current climate projections, fewer
of these blocking events will occur as temperatures rise. However, the
timing of such a reduction is currently highly uncertain. Meanwhile,
recent studies indicate that using climate models with high enough ocean
resolutions to simulate mesoscale eddies improve simulated winter
Euro-Atlantic blocking events significantly. In this paper, we show from
a large ensemble of climate simulations based on the highest emission
scenario that largely prominent and coarsely resolved non-eddying
climate models project a noticeable significant decline in blocking
frequencies from the 2030s-2040s, whereas blocking statistics in
eddy-permitting simulations are noticeably decreasing only from years
2060s. Our result suggests with a strong level of confidence that winter
blocking activity over the next several decades will keep being
dominated by internal variability.